The typical, traditional way for the engineering, procurement and construction of a structure, such as a building, a plant, a bridge or a machine or vehicle is as follows. At the beginning, there is a demand, for example of a customer, and the process for realization starts with the design of the structure. In case that a support structure for the building or plant is required, the design step includes also the design of the support structure, for example supported by a digital terrain model as a further input.
When the design of the whole structure is finished, thus allowing for an overview, the various parts for the structure are designed, and typically, related CAD data and specifications for the parts are generated. Then, nowadays a virtual assembly of the structure, eventually including a support structure, is created using a “virtual assembly” module of computerized design and construction tools. A list of needed parts is established and, depending on availability, it is determined which parts can be purchased as standard parts and which parts, as “special parts”, have to be specially manufactured, eventually by a subcontractor, to whom then construction drawings are sent. The step of organizing the acquiring of the needed parts, including the mailing of purchase orders and requiring specification of delivery times, is typically performed using logistic means, which may also be integrated in the design tools.
After receipt of the parts, these are sent to the construction location where the assembly will be done. This means that specially manufactured parts will be shipped by the subcontractor directly to the assembly location, and the standard parts will be delivered from the supplier's stock to the assembly location.
The assembly will start in the order that is described by the assembly list (created from the “virtual assembly” module), assuming that all parts will fit together. If there are deviations in fitting, dimensions of tools etc., these issues are addressed by rework at the construction site, which typically involves significant difficulties, as typically in the construction environment an optimum infrastructure or equipment with manufacturing tools for the parts is often not given. In the worst case, parts have to be disassembled and sent back to the supplier for rework or exchange. These repair-type works are typically costly and can lead to significant delays and a replication of work steps, which is not at all efficient. A simple example of a problem that might arise at the construction site may be meeting two pipes that should be welded together but do not meet, such that they may have to be forced together and then welded, what would mean introducing stress into the system, thus impairing stability and potential life time of the structure.
In the case of a building or plant to be erected on a support structure, after design of the support structure first there will be a stake out of support positions for the support structure, before the support structure is built from the acquired related parts. Even if the parts or already pre-manufactured sub-assemblies for the building/plant arrive in a correct state as planned at the construction site, problems may arise if the support positions/orientations are not correct. This could, for example, cause a need for adjusting/changing the support positions or the support structure, which typically is very costly at this stage of the process.
For supporting construction processes and organizing an assembling of parts to form structures thereof, different approaches are known. For example the patents DE 10 2008 062 458 A1 and DE 10 2009 037 830 B3 each disclose devices for the measuring of large assembly parts.
DE 10 2008 062 458 A1 discloses a laser-based measuring device for use during manufacturing processes in machine and equipment construction. The device has a laser utilized as a light source and an optical sensor, e.g. a charge coupled device (CCD) matrix sensor, where an object to be measured is provided in the laser radiation beam path of the laser. A first polarizing filter is provided in the radiation beam path, where adjustment of a polarization plane corresponds to a direction of linear polarization of the laser radiation. A second polarizing filter is arranged in the radiation beam path such that the orientation of its polarization plane is twisted with respect to the polarization plane of the first polarizing filter. Additionally, a color filter is placed in the radiation beam path in order to allow only pass of radiation of the laser emission wavelength.
DE 10 2009 037 830 B3 discloses a device and a method for measuring the surface of assembly parts, particularly of large components, using a scanning system on a measuring arm. The scanning can be done either mechanically in a tactile manner or optically using a laser. The device can be positioned and fixed on the assembly part. Then the arm, which has a fixed reference point with respect to the assembly part, is driven by a drive unit and an area of the surface of the assembly part is measured. This step is repeated until the assembly part has been measured completely.
EP 1653191 A1 discloses an apparatus for presenting differences between objects, such as an actual position and posture of an input target object, in real space and their corresponding design information in virtual space, for example as stored figuration information of the target object. The apparatus includes a superposed image generation unit, configured to generate an image which is obtained by superposing and displaying the image of the target object input from the image input unit and the stored figuration information of the target object. The apparatus includes a three-dimensional CAD with a three-dimensional design information storage unit configured to store three-dimensional design information of the target object. The apparatus is dedicated for facilitating the adaptation of the actual real target object to its design, particularly related to the construction process of a plant or factory facility.
Several studies have been published which address the introduction of virtual reality (VR) in architecture and in the construction process.
The use of 4D/VR in the construction of a high-rise apartment and commercial store building project in South Korea is described in Kim et al (2001). The biggest gain from using 4D/VR models was achieved from improving communication between managers and workers which led to reducing the construction time from 43 months to 39 months (Kim W., Lim H. C, Kim O., Choi Y. K. and Lee I.-S. (2001), “Visualized construction process on virtual reality”, Proceedings of the Fifth International Conference on Information Visualisation, IEEE Computer Society, Los Alamitos, Calif., USA, pp 684-689).
The use of VR in the construction of a new lecture hall in Helsinki was studied by Savioja et al (2003). The study described the process starting from a relative simple VR model for presentation of the concept and layout. The model was further detailed until a photo realistic model of the building could be presented and used for detailed studies of the design (Savioja L., Mantere M, Iikka O., Ayräväinen S., Gröhn M. and Iso-Aho J. (2003), “Utilizing virtual environments in construction projects”, Electronic Journal of Information Technology in Construction (ITcon) Vol. 8, pp 85-99).
Woksepp et al. (2004) investigated how a VR model was experienced and assessed by the users in the construction of a large hotel and office building, and the extent to which such model could complement the 2D CAD drawings that are mainly employed in such a context (Woksepp S., Tullberg O. and Olofsson T. (2004), “Virtual reality at the building site: investigation how the VR model is experienced and its practical applicability”, Proceedings of European Conference on Product and Process Modeling in Construction (ECPPM 2004), Istanbul, Turkey, 8-10 September).
Ganah et al (2005) presented a research project with the aim to develop a visualisations system for graphical communication of constructability information between design and construction teams. The objective was to improve the lack of communication between design and construction using visualisation tools (Ganah A. A., Bouchlaghem N. B. and Anumba C J. (2005), “VISCON: Computer visualisation support for constructability, Electronic Journal of Information Technology in Construction (ITcon), Vol. 10, pp 69-83).
Recently, also efforts have been undertaken in order to introduce VR in the construction process as a tool to support the design and construction process, besides only use as a visualization tool. A case study was published which described the use of VR in a construction project by providing values achieved and examples from how the customer, design teams and planning teams have been using VR models as a complementary source of information to 3D CAD models and 2D CAD drawings in the construction of a large-scale pelletizing plant (MK3) in northern Sweden. The research objective was to provide new insights and knowledge about the values of using VR models in a construction projects with focus on the design and planning process (Woksepp S., Olofsson T., “Using virtual reality in a large-scale industry project, ITcon Vol. 11 (2006), pp 627-640). Within this construction project, an iterative design process concerning, besides others, mechanics, electrical installations and the control system and involving the development of digital mock-up models, which were subjected to modifications for eliminating design errors in the course of the project, was developed.
The above described approaches, however, are all related only to parts of the process for engineering, procurement and construction of a structure, but do not present a solution for the process as a whole.